Search results for "Cold"
showing 10 items of 660 documents
Harrison-Zel'dovich primordial spectrum is consistent with observations
2010
Inflation predicts primordial scalar perturbations with a nearly scale-invariant spectrum and a spectral index approximately unity (the Harrison--Zel'dovich (HZ) spectrum). The first important step for inflationary cosmology is to check the consistency of the HZ primordial spectrum with current observations. Recent analyses have claimed that a HZ primordial spectrum is excluded at more than 99% c.l.. Here we show that the HZ spectrum is only marginally disfavored if one considers a more general reionization scenario. Data from the Planck mission will settle the issue.
Impact of general reionization scenarios on extraction of inflationary parameters
2010
Determination of whether the Harrison-Zel'dovich spectrum for primordial scalar perturbations is consistent with observations is sensitive to assumptions about the reionization scenario. In light of this result, we revisit constraints on inflationary models using more general reionization scenarios. While the bounds on the tensor-to-scalar ratio are largely unmodified, when different reionization schemes are addressed, hybrid models are back into the inflationary game. In the general reionization picture, we reconstruct both the shape and amplitude of the inflaton potential. We discuss how relaxing the simple reionization restriction affects the reconstruction of the potential through the c…
Dissociation of theophylline uptake and inotropic effect in myocardial tissue: influence of temperature, pH and calcium.
1975
1. The myocardial uptake and the positive inotropic effect of theophylline (100 mug/ml; 0.56 mM) were studied in isolated electrically driven guinea-pig hearts perfused by the Langendorff technique under various extracellular conditions. [3H]-theophylline was used. 2. Variations in temperature, hydrogen ion and calcium ion concentrations of the perfusion media changed the time course and magnitude of the effect of theophylline on myocardial twitch tension but did not affect the time course and amount of theophylline uptake. 3. Under all conditions, the build-up of the positive inotropic effect of theophylline was about three times faster than the uptake of the drug into the heart. 4. Since …
Temperature–Time Relationship in Collembolan Response to Chemical Exposure
1999
Abstract Effects of temperature on chemical toxicity to a collembolan, Folsomia candida , in relation to time were studied in this experiment. Field soil was used as a test substrate. Collembolans were incubated at three different temperatures (+13, +16, and +19°C) and in two different dimethoate concentrations (1 and 3 mg/kg), clean soil serving as the control. Four destructive samplings were done at 2-week intervals. Dimethoate degradation was also analyzed. Dimethoate 1 mg/kg had a slight effect on both adult growth and reproduction, whereas 3 mg/kg was fatal to F. candida in the soil used. Toxic effects tended to last longer at low temperature than at high temperature, but the differenc…
A comparison of the transcriptome of Drosophila melanogaster in response to entomopathogenic fungus, ionizing radiation, starvation and cold shock
2015
Background The molecular mechanisms that determine the organism's response to a variety of doses and modalities of stress factors are not well understood. Results We studied effects of ionizing radiation (144, 360 and 864 Gy), entomopathogenic fungus (10 and 100 CFU), starvation (16 h), and cold shock (+4, 0 and -4°C) on an organism's viability indicators (survival and locomotor activity) and transcriptome changes in the Drosophila melanogaster model. All stress factors but cold shock resulted in a decrease of lifespan proportional to the dose of treatment. However, stress-factors affected locomotor activity without correlation with lifespan. Our data revealed both significant similarities …
Lambda-doublet specificity in the low-temperature capture of NO(X Π21/2) in low rotational states by C+ ions
2009
Following our general approach to Lambda-doubling specificity in the capture of dipolar molecules by ions [M. Auzinsh et al., J. Chem. Phys. 128, 184304 (2008)], we calculate the rate coefficients for the title process in the temperature range 10(-4)<T<10(2) K. Three regimes considered are as follows: (i) nonadiabatic capture in the regime of high-field Stark effect with respect to the Lambda-doubling components, (10(-1)<T<10(2) K), (ii) adiabatic capture in the regime of intermediate Stark effect (10(-3)<T<10(-1) K), and (iii) adiabatic capture in the limit of very low temperatures (T<<10(-3) K) in the regime of quadratic Stark effect with respect to the Lambda-doubling and hyperfine compo…
Empirical calibration of the clumped isotope paleothermometer using calcites of various origins
2014
We present the first universal calibration of the clumped isotope thermometer for calcites of various mineralizing types. These are an eggshell of an ostrich, a tropical bivalve, a brachiopod shell, cold seep carbonate, and three foraminifera samples that grew between 9 and 38 C. CaCO3 was digested at 90 C using a common acid bath. Considering a difference in phosphoric acid fractionation factors between reaction at 25 and 90 C of 0.069& (Guo et al., 2009), the function between growth temperature T and the excess of 13 C– 18 O bonds in the evolved CO2 is expressed by a linear regression between 1/T 2 and absolute D47 (R 2 = 0.9915):
Flow phenomenon of micron-sized particles during cold spray additive manufacturing: High-speed optic observation and characterization
2020
Abstract A high-speed laser shadowgraph observation of the particles flow during cold spraying enables a good phenomenological characterization. The particles in-flight behaviour develops a kinematics with two regimes regardless the powder nature. When leaving the nozzle, the particles form a regime of uniform jet over a certain distance along the flow direction, and then a regime of sparse jet while particles deviate in the radial direction. This dispersion increases away from the nozzle exit and exhibits thereby an event of oblique collision during an additive route process. Under such conditions, kinematic deficiency prevails since oblique collision has shown to alter the deposition effi…
Plasma cell-free DNA in diagnostic KRAS mutation testing
2015
Epidermaalisen kasvutekijän reseptorin (EGFR) monoklonaalisia vasta-aineita (mAb) käytetään apuna metastaattisen kolorektaalisyövän (mCRC) hoidossa. Aktivoivat mutaatiot KRAS- ja NRAS-onkogeeneissä tekevät syöpäsolut vastustuskykyisiksi anti-EGFR-vasta-aineille, ja tästä syystä tuumorit tulee genotyypittää ennen hoidon aloittamista. Kudosbiopsian ottaminen on kuitenkin invasiivinen toimenpide, eikä näyte välttämättä edusta kattavasti syövän kaikkien solupopulaatioiden geneettisiä muutoksia. Verenkierron solunulkoisen DNA:n (cfDNA) on havaittu sisältävän maligneista soluista lähtöisin olevia onkogeenisiä mutaatioita, ja se voi olla hyvä vaihtoehtoinen tuumoriperäisen DNA:n lähde. Kehitimme j…
Renal Transplantation by Automatic Anastomotic Device in a Porcine Model
2015
Automatic vascular staplers for vascular anastomoses in kidney transplantation may dramatically reduce the operative time and, in particular, warm ischemia time, thus increasing the outcome of transplantation. Ten pigs underwent kidney auto-transplantation by automatic anastomotic device. Kidneys were collected by laparotomy with selective ligations at the renal hilum and perfused with cold storage solution. To overcome the shortage in length of renal hilum, a tract of the internal jugular vein was harvested to increase the length of the vessels. The anastomoses were totally performed by the use of the anastomotic device. On 10 kidney transplants, nine were successful and no complications o…